Cu/Zn-ZIF-8 derived yolk–shell ZnO supported Cu nanoparticles for mild hydrogenation of CO 2 to methanol

Cu/ZnO catalyst has been widely studied for selective hydrogenation of greenhouse gas CO₂ to value-added methanol but it remains challenging for obtaining methanol under mild condition. Here we show utilizing the typical bimetallic zeolitic imidazolate framework-8 (known as Cu/Zn-ZIF-8) as precursors to construct polycrystalline yolk-shell typed ZnO (p-ZnO_yk) supported Cu nanoparticles, denoted as Cu/p-ZnO_yk, for selective hydrogenation of CO₂ to methanol. This catalyst exhibits 98.5% selectivity of methanol and its production rate up to 15.8 mg h^-1 g_cat^-1 at a CO₂ conversion ratio of 1.5% under 180°C and 3 MPa CO₂/H₂ (1/3) as well as long-term stability for 500 h reaction on stream, superior to the reported Cu based catalysts under mild condition. Various spectroscopic analyses reveal that this yolk-shell structured catalyst exhibits strong interfacial electron transfer from Cu nanoparticles to p-ZnO_yk in Cu/p-ZnO_yk, which generates Cu⁺ active sites, facilitating the adsorption and activation of CO₂ at the interface and enhancing methanol production via formate pathway. This work provides a strategy for constructing novel structured Cu-ZnO hybrid catalyst with strong interfacial electron effect for significantly boosting CO₂ hydrogenation to produce methanol.